content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2011, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
   * Other names may be trademarks of their respective owners.]
   *
   * ------------
   * Dataset.java
   * ------------
   * (C) Copyright 2000-2008, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes (from 18-Sep-2001)
   * --------------------------
   * 18-Sep-2001 : Added standard header and fixed DOS encoding problem (DG);
   * 15-Oct-2001 : Moved to a new package (com.jrefinery.data.*) (DG);
   * 22-Oct-2001 : Changed name to Dataset.java (DG);
   * 17-Nov-2001 : Added getLegendItemCount() and getLegendItemLabels() methods,
   *               created SeriesDataset interface and transferred series related
   *               methods out (DG);
   * 22-Jan-2002 : Reconsidered (and removed) the getLegendItemCount() and
   *               getLegendItemLabels() methods...leave this to client code (DG);
   * 27-Sep-2002 : Added get/setDatasetGroup() methods (DG);
   * 10-Jan-2003 : Updated Javadocs (DG);
   *
   */
  
  package org.jfree.data.general;
  
  /**
   * The base interface for data sets.
   * <P>
   * All datasets are required to support the {@link DatasetChangeEvent}
   * mechanism by allowing listeners to register and receive notification of any
   * changes to the dataset.
   * <P>
   * In addition, all datasets must belong to one (and only one)
   * {@link DatasetGroup}.  The group object maintains a reader-writer lock
   * which provides synchronised access to the datasets in multi-threaded code.
   */
  public interface Dataset {
  
      /**
       * Registers an object for notification of changes to the dataset.
       *
       * @param listener  the object to register.
       */
      public void addChangeListener(DatasetChangeListener listener);
  
      /**
       * Deregisters an object for notification of changes to the dataset.
       *
       * @param listener  the object to deregister.
       */
      public void removeChangeListener(DatasetChangeListener listener);
  
      /**
       * Returns the dataset group.
       *
       * @return The dataset group.
       */
      public DatasetGroup getGroup();
  
      /**
       * Sets the dataset group.
       *
       * @param group  the dataset group.
       */
      public void setGroup(DatasetGroup group);
  
  }
  